Heat energy recovery system

ABSTRACT

A heat energy recovery system recovers heat energy from a fluid having a first temperature flowing through a conduit. The conduit includes a manifold chamber through which the fluid flows. A manifold conduit is located within the manifold chamber and contains a fluid heat storage material at a second temperature lower than the first temperature. A storage assembly has a chamber enclosed therein and fluidly coupled with the manifold conduit for storing the fluid heat storage material. The heat energy can be transferred from the fluid having the first temperature to the fluid heat storage material having the second temperature.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a system for recovering heat energy from household systems.

2. Description of the Related Art

Appliances in the home such as hot water heaters, furnaces, dryers, and the like exhaust hot air to the outside of the home, wasting heat energy that could otherwise be used.

SUMMARY OF THE INVENTION

A heat energy recovery system including a process chamber. Wherein a manifold conduit such as a pipe passes through the walls of the chamber at two locations to provide a winding within the process chamber such that as heated exhaust air from a household appliance flows through the process chamber, heat energy is retained by water flowing within the manifold conduit. The manifold conduit is in fluid communication with a thermally insulated tank defining a chamber therein which can contain the water and be used for retaining the higher volumes of heat energy, the chamber inside of the tank is airtight with respect to the atmosphere, and insulated such that heat energy from the water will not be lost. The heat energy recovery system further includes a pump and control system for recirculating the water from the manifold conduit to the insulated tank or to divert the heated water to other locations within the house such as a water heater.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a heat energy recovery system according to an embodiment of the invention.

FIG. 2 is a perspective view of an exemplary manifold conduit according to one embodiment of the invention.

FIG. 3 is a side view of an exemplary manifold conduit according to another embodiment of the invention.

FIG. 4 is a top view of an exemplary manifold conduit according to another embodiment of the invention.

FIG. 5 is a partially schematic plan view of the controller illustrated in FIG. 1.

FIG. 6 is a perspective view of a processing chamber to be used with the dryer illustrated in FIG. 1 with a cutaway to show an interior portion of the chamber.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

Referring to the drawings, and in particular to FIG. 1, an embodiment of the invention is illustrated comprising a heat energy recovery system 10 including a process chamber 12, and a storage assembly 14 for storing a fluid heat storage medium. Exhausted air from a dryer 16, a furnace 18, or a water heater 20 can be directed through the process chamber 12. A heat energy transfer takes place between the exhausted air, also known as a fluid having a first temperature, and a fluid heat storage medium, also known as a fluid having a second temperature, that is flowing through a manifold conduit 22 (shown in phantom) within the process chamber 12. It is typical that in a domestic hot water system the fluid heat storage medium would be water.

The heat energy recovery system 10 can include one or several processing chambers 12. For example, a user may wish to only recover heat energy lost from the drying process and thus only one processing chamber would be used. Alternatively, a user may wish to be highly efficient and separate processing chambers 12 can be connected to all of the above-mentioned household appliances as shown in FIG. 1. The processing chamber 12 can be fabricated in such a way that it can connect directly to a standard exhaust pipe 24 coming from the dryer 16, the furnace 18, or the water heater 20.

The processing chamber 12 can include an enclosure body 26 that defines an interior space through which fluid from the exhaust pipe 24 can flow. The enclosure body 26 can be made out of galvanized steel, aluminum, or other suitable material. The enclosure body 26 can be insulated and sealed with a suitable insulation such as fiberglass batting, aluminum foil, rubber foam, or plastic. Each processing chamber 12 has an inlet to direct exhaust from the household appliance to the interior space. Each processing chamber has an outlet to receive exhaust from the interior space and to direct the exhaust outside of the processing chamber 12. Normally, such exhaust would be vented outside the house.

The interior chamber can contain a manifold conduit 22 (shown in phantom) for assisting in the heat energy recovery process. The manifold conduit 22 has an inlet fluid port 28 that extends inward through the enclosure body 26 into the interior chamber and an outlet fluid port 30 that extends outward through the enclosure body 26. The inlet fluid port 28 connects with a feed hose 32 and the outlet port connects with a return hose 34.

The storage assembly 14 can include a cabinet 36 enclosing a fluid storage tank 38 (shown in phantom) to which the feed hoses 32 and return hoses 34 are fluidly coupled. The fluid storage tank 38 can be made of fiberglass, steel, PVC or other suitable material, and can be insulated. Preferably, the fluid storage tank 38 will have the ability to handle 150 psi or more of pressure before failure. The storage assembly 14 can also have a relief valve 40 and a drain valve 42 for the fluid storage tank 38 that can be provided on an exterior of the storage assembly 14 and immediately accessible by the user or hidden behind a cover, such as an access panel, hatch, or door. The storage assembly 14 is shown adapted for use with a typical wall outlet 44 to power the heat energy recovery system 10.

Thus, the manifold conduit 22 in each process chamber 12 has an inlet connected to the fluid storage tank 38 to receive the water to flow therethrough, and an outlet connected to the fluid storage tank 38 to return the water. The exterior of the manifold conduit 22 contacts the exhaust from the household appliance to derive heat energy therefrom while the interior of the manifold conduit 22 contacts the water to supply heat energy thereto. The manifold conduit 22 can be made out of copper metal or any suitable high thermal conductivity material to facilitate the heat energy transfer from the exhaust to the manifold conduit 22 to the water.

FIG. 2 represents an example of one embodiment of a manifold conduit 44. The manifold conduit 44 has an inlet port 46 that extends inward through the enclosure body 26 into the interior chamber of the process chamber 12 and an outlet port 48 that extends outward through enclosure body 26. The inlet port 46 connects with a feed hose 32 and the outlet port connects with a return hose 34. The manifold conduit 44 also includes heat energy transfer boxes 50 that can be made of a high conductivity material. These heat energy transfer boxes 50 are fluidly connected to each other and the inlet port 46 and outlet port 48 through connector conduits 52. Both the heat energy transfer boxes 50 and connector conduits 52 contact the exhaust from the household appliance to derive heat energy therefrom while the interior of the heat energy transfer boxes 50 and connector conduits 52 contacts the water to supply heat energy thereto. Preferably, the heat energy transfer boxes 50 are oriented in the enclosure body 26 so that the heated exhaust flows longitudinally between and along the boxes 50.

FIGS. 3 and 4 depict a second embodiment of the manifold conduit 54 wherein the conduit is assembled into a coil structure to increase the surface area available for the heat energy transfer and to efficiently distribute water into and throughout the manifold conduit 54 thereby maintaining a uniform temperature in the water. The manifold conduit 54 has an inlet port 56 that extends inward through the enclosure body 26 into the interior chamber of the process chamber 12 and an outlet port 58 that extends outward through enclosure body 26. The inlet port 56 connects with a feed hose 32 and the outlet port 58 connects with a return hose 34.

The manifold conduit 54 comprises a generally rectilinear outer framework 140. The framework 140 comprises end tubes 142, each formed into a generally identical rectilinear configuration, and fluidly coupled by longitudinally disposed parallel header conduits 62 and longitudinally disposed parallel connector conduits 64. Each conduit 62, 64 is fluidly coupled with one side tube 144 of an opposed pair of end tubes 142 at the midpoint of the side tube 144.

Each pair of opposed conduits 62, 64 is fluidly coupled to one of a plurality of generally identical heat energy transfer coils 60. The heat energy transfer coils 60 are formed into a generally rectilinear frame-like configuration, each coil 60 being parallel to the end tubes 142 and to each other. The heat energy transfer coils 60 occupy the midportion of the framework 140. The coils 60 are alternately coupled with a pair of header conduits 62, and connector conduits 64, as illustrated in FIG. 4, and with the ports 56, 58. Thus, for example, one of the outermost coils 60 can be coupled with a pair of heater conduits 62, and the adjacent coil 60 can be, in effect, rotated 90° and coupled with a pair of connector conduits 64. The next adjacent coil 60 can be oriented so that it is coupled with the pair of heater conduits 62, this alternating orientation being repeated for all of the coils 60. The interconnection of the framework 140 and heat energy transfer coils 60 provides a relatively large heat transfer area while enabling the efficient distribution of the water throughout the manifold conduit 54.

The exterior of the heat energy transfer coils 60, header conduits 62, connector conduits 64, and end tubes 142 contacts the heated exhaust fluid from the household appliance to derive heat energy therefrom, while the interior of the heat energy transfer coils 60, header conduits 62, connector conduits 64, and end tubes 142 carries the fluid having a second temperature, also known as the fluid heat storage medium, which receives heat energy from the heat energy transfer coils 60, header conduits 62, connector conduits 64, and end tubes 142, to thereby raise the temperature of the fluid heat storage medium.

One example of the manifold conduit 54 has been described and illustrated. Other configurations can be employed. For example, the configuration of the outer framework and the heat energy transfer coils can be circular, polygonal, or other suitable configurations. The longitudinal and lateral dimensions can be selectively increased or decreased. For example, the length can be increased, thereby enabling a greater number of coils 60 to be utilized. With a greater number of coils and/or an increase in lateral dimensions, additional header conduits 62 and connector conduits 64 can be used and coupled with the coils 60 to facilitate the efficient distribution of the water throughout the larger manifold conduit 54.

Referring back to FIG. 1, the storage assembly 14 can be provided with a control panel 66 with operational controls enabling a user to input commands to a controller 68, which controls a control assembly 72. The control panel 66 can have any number of features common to a control panel 66, including but not limited to a power button, parameter adjusting buttons and dials, a display, and start and stop buttons. These features can be marked with appropriate indicia to indicate their function. Operating the heat energy recovery system 10 can require a user to manipulate several of these features to initiate operation of the system 10 and specify desired parameters. Examples of such parameters include, but are not limited to, water temperature desired, or humidity desired. As illustrated in FIG. 1, the controller 66 can be connected with each of the processing chambers 12 through a communication cable 70.

FIG. 5 is a partially schematic plan view of an embodiment of a control assembly 72 of the invention. The control assembly 72 circulates the fluid heat storage means within the heat energy recovery system 10 and can selectively divert the fluid heat storage means outside of the heat energy recovery system 10 as desired by the user. The control assembly 72 can include a controller 68, a pump 74, valves 76, 78, 80, 82, 84 operably coupled to the controller 68 to direct the flow of the fluid heat storage material, a temperature sensor 86 (FIG. 1), a humidity sensor 88 (FIG. 1), conduits 90, and control leads 92. The conduits 90 fluidly couple the pump 74 and the valves 76, 78, 80, 82, 84 with the water heater, a domestic water supply, the fluid storage tank, and the manifold conduits.

The remainder of the discussion regarding the control assembly 72 will be in the context of a domestic hot water system wherein the fluid heat storage medium is water. In essence, the heat energy recovery system 10 is fluidly coupled with a water supply, such as a local water utility, or a private well. A water heater can be coupled with the water supply to provide heated water to household users. Alternatively, the water can be diverted by the control assembly 72 so that otherwise unused heat energy can supplementally heat the water prior to the water entering the water heater and being distributed.

Referring again to FIG. 5, water from the water supply can be directly provided to the water heater 20 by opening the valve 80 and closing the valves 78, 82. Water from the water supply can be diverted to the manifold conduit 22, when heated exhaust is generated, by opening the valves 80, 82, and 84, and closing the valve 78. The fluid storage tank 38 can receive water from the manifold conduit 22 of one or more process chambers 12 in use with the heat energy recovery system 10 through the return hose 34. The pump 74 circulates the water from the manifold conduits 22 either to the fluid storage tank 38 or to the water heater 20. Water can flow to the fluid storage tank 38 by opening the valve 76 and closing the valve 78. Water can flow to the water heater 20 by opening the valves 76, 78, and 80, and closing the valve 82.

Water can also be supplied from the fluid storage tank 38 to the manifold conduit 22 of one or more process chambers 12 when the valve 84 is open and the valve 82 is closed. Alternatively, water can be supplied from the fluid storage tank 38 to the water heater 20 when the valve 82 is open and the valves 80, 84 are closed. To maintain a selected water level in the heat energy recovery system, the fluid storage tank 38 can also receive water directly from the water supply. Valve 78 must be open to distribute water from a domestic water supply to the fluid storage tank 38. If valve 78 is closed but valve 80 is open, the water supplied by the domestic water supply can be distributed to water heater 20.

For water to be directed from the manifold conduits 22 to the water heater 20 through the water heater feed 94, the valves 74, 76, 78, 80 must be open, and valve 82 must be closed.

The temperature sensor 86 in the process chamber 12 can sense the temperature of heated exhaust from the furnace 18, and send a signal through the communication cable 70 and control lead 92 to the controller 68 to operate the heat energy recovery system 10. The controller 68 can then signal the appropriate valves 76, 78, 80, 82, 84 and the pump 74 to supply water from the fluid storage tank 38 to the manifold conduit 22. The water can travel from the fluid storage tank 38 housed in the storage assembly 14 through a feed hose 32 and into the inlet fluid port 46. After traveling through the manifold conduit 22 (FIG. 1) the water can exit through the outlet fluid port 48 and travel through a return hose 42 before returning to the control assembly 72.

Once inside the control assembly, the water can be pumped by the pump 74 to either the fluid storage tank 38 or the water heater 20. The user can choose where the water is to be distributed, and input the selection into the control panel 66. The water can even be directed outside of the heat energy recovery system 10 and into the water heater 20 where the water can be utilized by the user. Thus, the water warmed through the heat energy recovery system 10 can be used in the household without a need for it being heated by the hot water heater.

The control assembly 72 can continue to circulate the water until the temperature sensor 86 senses no more hot air is being introduced inside the process chamber 12. Alternatively, the control assembly 72 can continue to circulate fluid having a second temperature until the temperature sensor 86 senses no more hot air is being generated, and the humidity sensor 88 senses no moist air inside the process chamber 12.

The control assembly 72 illustrated in FIG. 5 is only one example of a control assembly configuration. For example, in a commercial self-serve laundry, multiple fluid storage tanks, water heaters, and manifold conduits can be utilized, necessitating a control assembly having a greater number of valves and pumps. Further, a fewer or greater number of conduits can be utilized depending upon the selected fluid line configuration. A fewer or greater number of sensors can be utilized depending on the number of process chambers 12 in use in the heat energy recovery system 10 and the degree of control desired. Control leads can be incorporated into the device based upon the components for which control by the controller 68 is desired.

In FIG. 1, the dryer 16 is illustrated as having the processing chamber 12 located on top of and behind the dryer 16 for ease of installation and control. If the dryer is located in the same room (not shown) as the storage assembly 14, the processing chamber 12 for the dryer can be located inside the storage assembly 14 to save space. FIG. 6 illustrates an alternate embodiment of a processing chamber 96 for the dryer 16 of FIG. 1.

The processing chamber 96 can include a cabinet 98 that defines an interior chamber 100 through which fluid from the dryer hot air exhaust pipe 24 can flow. The processing chamber 96 can include an inlet port 102 for receiving the heated exhaust air and directing it to the interior chamber 100. The processing chamber 96 can include an outlet port 104 for directing exhaust air outside of the processing chamber 96.

The interior chamber 100 can contain a manifold conduit 106 for assisting in the heat energy recovery process. The manifold conduit 106 has a conduit inlet port 108 that extends inward through a wall of the cabinet 98 into the interior chamber 100 and a conduit outlet port 110 that extends outward through a wall of the cabinet 98. The conduit inlet port 108 connects with a feed hose 32 and the conduit outlet port 110 connects with a return hose 34. Thus, the manifold conduit has an inlet connected to the fluid storage tank 38 through the control assembly 72 to receive the water to flow therethrough, and an outlet connected to the fluid storage tank 38 through the control assembly 72 to return the water. The exterior of the manifold conduit 106 contacts the exhaust from the household appliance located in the interior chamber 100 to derive heat energy therefrom while the interior of the manifold conduit 106 contacts the water to supply heat energy thereto.

Instead of utilizing heated exhaust air to heat water, the hot dryer exhaust can be diverted into a room to heat the room. The processing chamber 96 can include a lint filter device 112. The lint filter device 112 can include a lint filter inlet port 114, a filter 116, and a lint filter outlet port 118. The lint filter inlet port 114 can be connected with the exhaust conduit 24 of the dryer 16 and the lint filter outlet port 118 can be connected to the inlet port 102 of the processing chamber 96 through a connector 120.

The processing chamber 96 can also include an air direction valve 122. The air directional valve 122 can receive the exhaust from the outlet port 104. The air directional valve 122 can then either direct the exhaust through a first exit port 124 into the room, or through a second exit port 126, the exhaust conduit 24, and outside the building. The air direction valve 122 enables a user to selectively redirected heat and humidity into the home. If it is desired that heat and humidity not be added into the interior of the home the first exit port 124 can be covered by a cover 128. Thus, the air directional valve 122 can be selectively used by the user to direct heat and humidity to the inside of the house, or to the outside of the house.

Activating the air direction valve 122 to direct the hot air exhaust directly into a building can be useful in the fall, winter, and spring seasons when additional heat and humidity may be desired. During the summer, a user can opt not to direct extra heat and humidity into the building, and thus the air valve control can be operated so that hot air is exhausted outside the building.

Alternatively, if the user wishes to direct additional heat, but not humidity, into the building, the cover 128 can be placed on the first exit port 124 and the exhaust air can be allowed to enter the chamber 130 through an air valve 132. By opening the air valve 132, exhaust air enters the chamber 130 before exiting the processing chamber 96 through the outlet port 104 and being directed outside of the house through the second exit port 126. The chamber 130 can be fabricated of a highly heat energy conductive material, such as copper, and heat energy can radiate from the chamber 130 into the building. When additional heat is not desired, the air valve 132 can be closed and exhaust air will not enter the chamber 130.

During operation of the dryer 16, hot moist air can be exhausted through the exhaust pipe 24 and into the lint filter device 112. The hot moist air exits the lint filter device 112 and enters the inlet port 102 of the processing chamber 96. As the hot moist air is directed through the processing chamber 96, it contacts the surface of the manifold conduit 106. The manifold conduit 106 absorbs heat energy from the hot moist air and cools the air. The hot moist air can cool down to the point that the moisture in the air becomes liquid water. This liquid water can drip down the inside of the processing chamber 96 and be drained through a drain port 134. The cooled air can exit the processing chamber 96 through an outlet port 104 where it can enter the air directional valve 122 to then be directed inside the home or outside the home, depending on the preference of the user.

The processing chambers connected with the furnace and hot water heater are similar but less complex than that required for the dryer and will not be described in detail. Such processing chambers do not contain a lint filter device, because one is unnecessary. Further, such processing chambers do not include an air direction valve. Thus, the cooled air exits from an outlet port of the processing chamber before being directed outside of the house.

While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the forgoing disclosure and drawings without departing from the spirit of the invention, which is defined in the appended claims. 

1. A heat energy recovery system for recovering heat energy from a first fluid having a first temperature flowing through a conduit, the system comprising: a conduit having a manifold chamber through which the first fluid flows; a manifold conduit located within the manifold chamber and containing a fluid heat storage material at a second temperature lower than the first temperature; a storage assembly having a chamber enclosed therein and fluidly coupled with the manifold conduit for storing the fluid heat storage material; wherein the heat energy is transferred from the first fluid having the first temperature to the fluid heat storage material having the second temperature.
 2. The system as defined in claim 1 further comprising a control assembly to recirculate the fluid heat storage material within the heat energy recovery system and to selectively divert the fluid heat storage material outside the heat energy recovery system.
 3. The system as defined in claim 2 wherein the control assembly further comprises: a controller; a pump; and at least one valve operably coupled to the controller to direct the fluid heat storage material outside the heat energy recovery system.
 4. The system as defined in claim 3 wherein the pump is actuated in response to a predetermined level of fluid heat storage material within the chamber.
 5. The system as defined in claim 1 wherein the tank is thermally insulated to inhibit heat energy flow between the chamber and the external environment.
 6. The system as defined in claim 1 wherein the fluid heat storage material is water.
 7. The system as defined in claim 1 wherein the manifold conduit is a pipe and the interior of the pipe provides fluid flow communication with the chamber, the interior of the pipe being sealed to prevent fluid flow communication between the manifold chamber and the interior of the pipe.
 8. A heat energy recovery system for recovering heat energy from exhaust air having a first temperature, the system comprising: a conduit having a manifold chamber through which the exhaust air flows; a manifold conduit located within the manifold chamber and containing water at a second temperature lower than the first temperature; a storage assembly comprising a chamber enclosed therein and fluidly coupled with the manifold conduit for storing the water; wherein the heat energy is transferred from the exhaust air to the water.
 9. A heat energy recovery system for a household appliance comprising: an appliance conduit fluidly coupled with the household appliance and defining a manifold chamber for conveying heated fluid from the household appliance; a storage tank defining a storage chamber therein; a quantity of water contained within the storage chamber; a manifold conduit housed within the manifold chamber, a portion of which extends inward through a wall of the appliance conduit into the manifold chamber and extends outward through a wall of the appliance conduit for fluid coupling of the manifold conduit with the storage tank, the storage tank storing water from the manifold conduit, a wall of the manifold conduit contacting the water to supply heat energy thereto. 